Carving tool



W. C. STENGER.

CARVING TOOL.

APPLICATIDN .FILED MAR. 29, 1920.

1,409,258, y Patented Mar. 14, i922.

L E@ ,4.4 o g55/Ewan?,

UNITED STATES PATENT OFFICE.

CARVIN G TOOL.

Specification of Letters Patent.

Patented Mar. 14, 1922.

Application led March 29, 1920. Serial No. 369,677.

To all whom t may concern:

Be it known that I, IVILLEBALD C. STEN- GER, a citizen of the United States, residing ,at Chicago, in the county of Cook and State of Illinois, have invented certain new and .useful Improvements vin Carving Tools, of which the followingis a specification, reference being had to the accompanying drawings, and to the reference characters marked thereon, which form a part of this speciication.

This .invention relates to improvements in cutting tools for wood carving machines and the method of making the same, and ymore particularly relates tothat type of tool illustrated in U. S. Letters Patent No. 1,330,287, issued to me on the 10th of February, 1920.

The principal object of my invention is to provide acutting tool in which circulatory vibration, .While the tool is in operation, shall be such a negligible quantity, that it ma y be said to be practically eliminated.

Another object is to provide a cutting tool, of the type referred to, in which more definite provision is made for carrying off the chips or shavings developed by the tool in operation, and while retaining all the advantages set forth and attained by thc tool described and claimed in my `former patent, shall attain the foregoing objects.

Another object of theinvention is to provide forthe carrying ofi', in addition to the chips, of those fine particles of grit which accumulate onthe cutter in the center of the Vzone of cutting area and prevent the rotary cutter from-taking as deep a cut in thewood asitwould otherwise d0. And finally, I desire to .provide a cutting tool which shall an improvement upon that shown in my priorpatent and which shall have a wider .range of utility.

Y u These and other-.advantagesof my present nventionwill be Vmore .apparent as I proceed `with my specification, the invention Vconsisting in the toolhaving the characteristics hereinatter mentioned and in themethod lof,producing it as described and more particularlypointed out lin the appended claims.

l In the drawings:

'Fig. 1 is a vview of myrnew cutting tool in side elevation.

.'Fig. Y2 is a similar view, the tool belng v turned ninety degree s. l Fig. 3 is a bottom plan view ofthe cutting tool.

Fig. 4 is a top plan view of the same.

Fig. 5 is a view in side elevation, showing a modified form of the cutting head.

Fig. 6 is a side elevation of the blank of which the tool is formed, showing its condition at the end of the first step in the method of manufacture.

Fig. 7 is a view showing the same blank in end elevation.

Fig. 8 is a side elevation of the blank shown in Fig. 6, illustrating the neXt operation in the method of manufacture of the tool.

Referring to that embodiment of my invention illustrated in Figs. 1 to 4 inclusive; the tool as a whole, indicated at A, comprises a shank B and cutting head C. The Vshank B is shown as relatively long and it may be cylindrical or of any other cross sectional contour to fit within or be secured to the particular rotatabletool-holdingr chuck with which it is to be used.

Near its lower end, said shank is flattened at diametrically opposite portions to provide the member which becomes the head C, said flattened portion gradually tapering upwardly to form shoulders 10. The margins 11 of this tapered part are spirally curved outwardly and then downwardly, as

Vclearly shown in Fig. 4, the tapered member .member from the outer margin inwardly to thefslit 12 is beveled to form a cutting :edge 15. These cutting edges, which extend radially as shown, while' straight in the'radial direction are, of course, shaped to conform tothe curvature given t the bottom 14 of the flange member 13, as clearly shown in Fig. 2. Thus the cutting edge 15 is of a -length equal tothe radius of the fiange or .wing member 13.

The thickness of each member 13 becomes gradually greater from the end on which its cutting edge 15 is formed until it merges Vwith the shoulder 10, and the .latter also gradually thickens as it merges into the .shank B, as plainly indicated in Figs. 1, 2

and 4. This strengthens the tool, prolongs its life, and gives it increased utility.

The slit 12 in the finished tool extends,

as shown, inthe central median line of they wings 13 is such as to bring the bottom of the two radial 'cutting edges 15 into a straight line or plane, as shown at 18, normal, (substantially horizontal), to a vertical plane running through the longitudinal aXis of the shank B. Vhen so shaped, the tool l is exceedingly effective in cutting plain or fiat surfaces. f

The method by which the tool thus described is fabricated, isA illustrated in Figs. 6,- 7 and 8, Vto which reference will now be made.

l first take a cylindrical body, or form a cylindrical body, and flattenits lower portion. This'step formsv the shank B, and a disc shaped lower portion, which becomes the cutting head C including the shoulders 1() andthe flanges or wings 13. It will be noted that this disc shaped part is tapered, being thickest at its upper `end as shown in Fig. 7. Y

I then stamp out or form the aperture 16 and cut out a segment D, as shown in Fig. 8 in dotted lines, from the lower portion of the disc. By severing the disc (usually by sawing) along the dotted line 19, preferably after the bending or twisting operation, a slit 12 is formed. The lower portions of the disc a're'bent or'twisted to the desiredconformation Vto forni the wings'llf, Finally 'l sharpen the edges of each wing to form cutting edges l5.

."This method permits of great accuracy in distributing the metal. The slit 12, being in accurate axial alignment with the shank B, is thus located in the center of the Zone swept by the cutting edges. The tool thus formed gives most accurate results.

This method also enables me to properly .position the aperturel to give the desired and best results, and also to form the cutting edge inY a straight, radial line before being sharpened, as well as to form a cutting edge the entire radial distance from theperiphery to the center of the head C.

It is also found that, by this method, the

twisting and forming of the flanges or wings :Lacasse 13 in the desired position is not only greatly facilitated but may be more accurately performed; "also that the desired twisting of the shoulder 10 to cooperate with the desired twist of the flanges or wings, may be the more accurately accomplished.

A characteristic of my new carving tool thus described is the balanced and symmetrical arrangement whereby two cutting edges are presented to the work. Tools having a single flange and cutting edge are what l characterize as unbalanced and require great care in their manipulation in use; and usually may not be rotated at very-high or very slow speeds without developing resisting force normal to the cutting edge which force causes a bending of the cutting flange or head relative to the fixed shank. VVThis'is not `only-weakening in its effect, sometimes breaking the'tool` but usually results in a circulatory vibration which producesinac curacies in the cutting operation.

In my present balanced and symmetrical tool, with its two cutting edges, the resisting force normal to the cutting edge of vone flange is balanced by a diametrically opposite and equal force normal to the cutting edge of the other flange, which eliminates all circulatory vibration and produces accuracy in the cutting operation, while the resultant Y Y of these two equal and opposite forces sets up a torque in the shank B and `head C double that found in similar tools where thereis but one cutting edge minus'the amount re-rV This aperture not only eliminates metal.

but provides a channel for the escapel of shavings. Thefine grit or wood fibres which Y are found in some 'woods morethan others, Y

and which inmost rotary cutting tools do Anot readily Vpass away as do the shavings, and,

which, adhering tothe inner or central part of the cutting edge prevent its perfect operatool to enter the slit 12, to pass upwardly therethrough into the aperture:16, to fall Yor pass laterally out of said aperture andrby being caught by the advancing inside or concave surface of the approaching fiange` or wings 13 to be cast off, as are the shavings. Thus the cutting edge15rper se is-automati cally kept clean and free so that `it can give 100% efciency so long as it is sharp. The

tion, will be'found in the `use of my improved configuration of the cuttingl head C, it will alsofrbe observed, is such that the cutting edge may be repeatedly sharpened not only with ease but without vvarying the conformation of the working surfaces of the headC.

That isv to say, the cutting away of'ther1v flanges or wings 13 by repeated sharpening operation upon the cutting edge 15 does not alter or substantially vary the angle or configuration of the cutting edge 15 or the under surface 14 of the head C.

It will be understood that in grinding the cut-ting edges of tools of this character, great difficulty is experienced in keeping the tool properly centered, which results in imperfect carving. In my improved tool, no such dficulty is experienced in grinding on account of the presence of the slit l2; thus great accuracy in the operation of the tool is attained.

I claim as my invention:

1. A carving tool having a shank member and an integral cutter member, the latter being a iattened, widened head divided at its lower part to form wings each having a cutting edge, the wings and the undivided part being spirally twisted and the wings bent back to steepen the pitch of the spira-l.

2. A carving tool comprising a shank member and an integral cutting head member, the latter comprising a pair of wings joined to the shank member by shoulders, a straight cutting edge on each wing, the wings and shoulders being tapered from the cutting edge to the shank and being also spirally twisted so that the cutting edge ot one wing shall stand diametrically opposite the cutting edge of the other.

3. A carving tool comprising a shank member and an integral cutting head member, the latter comprising a pair of wings joined to the shank by shoulders, a straight cutting edge on each wing, the wings and shoulders being uniformly tapered from the cutting edge to the shank and being also spirally twisted to form diametrically opposite cutting edges.

Ll. A carving tool comprising a shank member and an integral cutting head member, the latter comprising a pair of Wings joined to the shank by shoulders, a straight cutting edge on each Wing, the wings and shoulders being tapered from the cutting edge to the shank, and being also uniformly spirally twisted to form diametrically opposite cutting edges.

5. A carving tool comprising a shank member and an integral cutting head member, the latter comprising a pair of wings spirally twisted about the shank member, a straight cutting edge on each wing the cutting head as a whole being tapered in thickness from the cutting edge to the shank, a shavings aperture in the cutting head and a slit or conduit extending from said cutting edges to said aperture.

6. A carving tool comprising a shank member and an integral cutting head member, the latter comprising a pair of tapered and spirally twisted wings, each having a straight cutting edge, thetaper being uniform from the cutting edge to the shank and the spiral twist being uniform, a shavings aperture and a slit or conduit extending from the cutting edges to said aperture.

In testimony that I claim the foregoing as my invention I affix my signature, in the presence of two Witnesses, this 27th day of March, 1920.

WILLEBALD C. STENGER.

Witnesses:

TAYLOR E. BROWN, B. L. MACGREGOR. 

